A new study published in the Journal of Bone and Mineral Research shows how bones in mammals are negatively impacted by calorie restriction, and particularly by the combination of exercise and calorie restriction. Maya Styner, MD, associate professor of medicine at the UNC School of Medicine, is the senior author on the study.
“These findings were somewhat of a surprise for us,” Styner said. “Past studies in mice have shown us that exercise paired with a normal calorie diet, and even a high calorie diet, is good for bone health. Now we’re learning this isn’t true for exercise along with a calorie-restricted diet.”
Styner’s research focuses on the fat in bone marrow of mice. Although fat in the bone is poorly understood, to date it is thought to be harmful to bones of mammals, including humans, because it makes bone weaker. Less fat is usually an indication of better bone health. Styner’s past studies have looked at the effects of calorie consumption on bone marrow fat, along with the role exercise plays. She’s found that in obesity caused by excess calories, the amount of bone marrow fat is increased. Exercise in both obese and normal weight mice decreased bone marrow fat and improved the density of bones. Continue reading